Opposition parties and civil society organisations say they will defy Public Enterprises Minister Barbara Hogan and continue lobbying the World Bank to reject the government's request for a R28billion loan.
Government is set to hear next month if the World Bank will grant the loan. Those opposed include the ID, Cope, Anti-Privatisation Forum, National Union of Metalworkers of South Africa and SA Council of Churches.
Hogan and Energy Minister Dipuo Peters told the organisations last week to stop opposing the loan.
But the Anti-Privatisation Forum accused Hogan of "toeing government's line" without considering the problems of building more polluting coal-fired power plants.
Apart from the higher prices people will have to pay for electricity next month, the public will also be left to pay back the expensive World Bank loan, said APF's Dale McKinley.
ID chief whip Lance Greyling said there was no need for the government to build two new coalfired power plants, and that the World Bank should only give the loan if the second Kusile power plant was scrapped.
"We are locking ourselves into a coal-based future without the country even having an energy plan. Kusile should be scrapped until we see how much we can save through energy efficiency."
The Kusile power plant will only be ready to provide electricity in seven years.
"By that time we could have used the money to build huge solar power plants like those in California," Greyling mooted.
Both Cope and the ID have asked the World Bank not to grant the loan unless ANC front company Chancellor House divests its shares in the Hitachi Consortium, which has a R38billion contract to install boilers in the new power stations.
Cope's Phillip Dexter said his party would not support the loan unless "more money was put into green and renewable energy".